Derivatized 3,4-Alkylenedioxythiophene monomers, methods of making them, and use thereof

ABSTRACT

The present invention relates to methods of making derivatized 3,4-alkylenedioxythiophene monomers and methods of using the 3,4-alkylenedioxythiophene monomers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/US2005/047188, filed Dec. 23, 2005, which claims the benefit of U.S.Provisional Application Nos. 60/640,563, filed Dec. 30, 2004 and60/694,393, filed Jun. 27, 2005, the disclosures of which areincorporated herein by reference in their entireties.

FIELD OF THE DISCLOSURE

The present invention is directed to processes for preparing derivatized3,4-alkylenedioxythiophenes having improved solubility in water, methodsof making them, and their use in electrical devices.

BACKGROUND

Poly(3,4-ethylenedioxythiophene) (PEDOT) is an important electricallyconductive polymer because of both its high conductivity and temperaturestability. Its monomeric unit, 3,4-ethylenedioxythiophene (EDOT),however, has poor solubility in water. While some water-soluble EDOTcompounds are known in the art, such as EDOT-CH₂OH, the known method ofmaking EDOT-CH₂OH involves a complex series of six reaction stepsstarting from thiodiglycolic acid. Thus, a need exists for improvedprocesses for making derivatized EDOT compounds having improvedsolubility in water.

SUMMARY

Provided are methods of making derivatized 3,4-alkylenedioxythiophenecompounds.

In one embodiment, the present invention comprises a process forpreparing a compound of Formula I:

wherein n is from 1 to 4, comprising contacting a compound of FormulaII:

wherein X is halogen and n is from 1 to 4; with an inorganic hydroxide,an alkali or alkaline earth metal carboxylate, an ammonium oralkylammonium carboxylate, an alkali or alkaline earth metal alkoxide,or an ammonium or alkylammonium alkoxide.

The

of Formula II can be a straight chain or branched. In some embodiments,the group can be substituted with moieties which do not interfere withthe chemistry in the process for forming the compound with Formula I. Insome embodiments, the substituents may also improve solubility, such as,for example, ether, ester, or carboxylate groups.

In one embodiment, the present invention comprises a process forpreparing a compound of Formula II:

comprising contacting a 3,4-dialkoxythiophene with anω-halo-1,2-alkanediol in the presence of an acid. In certainembodiments, the ω-halo-1,2-alkanediol is a 3-halo-1,2-propanediol.

In one embodiment, the present invention comprises a process forpreparing a compound of Formula V:

wherein m is 1 or 2 and p is 2 or 3, comprising contacting a compound ofFormula VI:

wherein X is halogen, m is 1 or 2 and p is 2 or 3; with an inorganichydroxide, an alkali or alkaline earth metal carboxylate, an ammonium oralkylammonium carboxylate, an alkali or alkaline earth metal alkoxide,or an ammonium or alkylammonium alkoxide.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes an illustration of an exemplary organic electronicdevice.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DETAILED DESCRIPTION

Provided are processes for preparing derivatized3,4-alkylenedioxythiophene compounds, the products produced by theprocesses, electronically conductive polymer compositions comprisingderivatized 3,4-alkylenedioxythiophene monomers, and devices thereof. Anexemplary derivatized 3,4-alkylenedioxythiophene compound of the presentinvention is (2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methanol, orEDOT-CH₂OH.

For use herein, the term EDOT-CH₂OH refers to a compound of Formula III:

In one embodiment, the present invention is directed to processes forpreparing derivatized 3,4-alkylenedioxythiophene compounds comprisingcontacting a compound of Formula II:

wherein X is halogen and n is from 1 to 4, with an inorganic hydroxide,alkali metal carboxylate, alkaline earth metal carboxylate, ammonium oralkylammonium carboxylate, alkaline earth metal alkoxide, alkali metalalkoxide, or ammonium or alkylammonium alkoxide, to provide a compoundof Formula I wherein n is from 1 to 4:

In one embodiment, n is 1 and the derivatized 3,4-alkylendioxythiophenecompound is EDOT-CH₂OH

In one embodiment, the inorganic hydroxide is an alkali metal hydroxide,an alkaline earth metal hydroxide, or an ammonium or alkylammoniumhydroxide. Exemplary alkali metal hydroxides include, for example, KOH,NaOH, or LiOH. Exemplary alkaline earth metal hydroxides include, forexample, Mg(OH)₂ or Ca(OH)₂.

In one embodiment, the contacting step is performed in the presence of acatalyst. The catalyst can be any molecule capable of facilitating thesynthesis reaction. In some exemplary embodiments, the catalyst is acrown ether. For use herein, the term crown ether refers to amacrocyclic polyether whose structure exhibits a conformation with aso-called hole capable of trapping cations by coordination with a lonepair of electrons on oxygen atoms. Each oxygen atom is bound between twoof the carbons atoms and arranged in a ring. Exemplary crown ethers foruse herein include 18-crown-6,15-crown-5,12-crown-4 or a combinationthereof.

In one embodiment, the conversion of a compound of Formula II to aderivatized 3,4-alkylenedioxythiophene compound, such as a 3,4-alcohol,is by a substitution reaction. A substitution reaction involvesreplacement of a leaving group by another functional group. In oneaspect, a substitution reaction entails reacting a compound of FormulaII with an hydroxide salt in one or more polar aprotic solvents. In someexemplary embodiments, the one or more crown ethers, one or morecryptands, sodium iodide, or a combination thereof can be used ascatalysts. The term cryptands refers to a macropolycyclicpolyazo-polyether, where the three-coordinate nitrogen atoms provide thevertices of a three-dimensional structure. Exemplary cryptands include,for example, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane.

In one embodiment, the conversion of a compound of Formula II to aderivatized 3,4-alkylenedioxythiophene compound, such as a3,4-alkylenedioxythiophene alcohol, is by a two-step procedure. Thefirst step is a substitution reaction using the salt of a carboxylicacid, e.g., sodium acetate, potassium acetate, ammonium acetate, sodiumbenzoate, potassium benzoate, and ammonium benzoate, in one or morepolar aprotic solvents to form an organic ester. The ester can then behydrolyzed to form the corresponding 3,4-alkylenedioxythiophene alcohol.

In one embodiment, an alkali metal alkoxide is used to convert thecompound of Formula II to a 3,4-alkylenedioxythiophene alcohol, e.g.,EDOT-CH₂OH. The alkali metal alkoxide can be used to form an ether thatis then converted to a 3,4-dioxyalkylenthiophene alcohol, e.g.,EDOT-CH₂OH, via one or more cleaving agents. Exemplary cleaving agentsinclude, for example, zinc or acetic acid. Exemplary alkalki metalalkoxides include, for example, sodium allyloxide such as sodium2-propen-1-oxide).

Also provided are processes for preparing a compound of Formula II

wherein X is halogen and n is from 1 to 4, comprising contacting a3,4-alkylenedioxythiophene with a halo-1,2-alkanediol in the presence ofan acid. In one embodiment, the halo-1,2-alkanediol has the formulaCH₂(OH)CH(OH)(CH₂)_(n)X, where n is from 1 to 4. Exemplary acidsinclude, but are not limited to, para-toluenesulfonic acid,methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroaceticacid, sulfuric acid, or any combination thereof.

In one embodiment, n is 1 and the 3,4-alkylenedioxythiophene iscontacted with 3-halo-1,2,-propanediol. In embodiments, wherein n is 2,3, or 4, 3,4-alkylenedioxythiophene can be contacted with otherhalo-1,2,-alkanediols including, for example, 3-bromo-1,2-propanediol,4-bromo-1,2-butanediol, 5-bromo-1,2-pentanediol, and the like.Halo-1,2,-alkanediols are readily available from commercial sources,such as Aldrich Company, Milwaukee, Wis., USA., can be synthesizedaccording to methods known in the art (Journal of Catalysis, 208(2),339-344, 2002; Synthesis, (4), 295-7, 1989), or through direct oxidationof ω-bromo-α-olefins using an oxidizing agent such as potassiumpermanganate or osmium tetroxide.

In one embodiment, the contacting step is performed in the presence of asolvent. Exemplary solvents include, but are not limited to aralkanes.In one embodiment of the present invention, the aralkane is toluene.Exemplary 3-halo-1,2-propanediols include 3-chloro-1,2-propanediol and3-bromo-1,2-propanediol.

In one embodiment, provided are processes for preparing a derivatized3,4-alkylenedioxythiophene comprising contacting 3,4-dihalothiophene,e.g., 3,4-dibromothiophene, with an alkoxide in the presence of copperand iodine reagents. In one embodiment, the 3,4-dialkoxythiophene is3,4-dimethoxythiophene. Exemplary alkoxides include, but are not limitedto, sodium or potassium methoxide. The copper and iodine reagents can beany compound capable of facilitating the synthesis reaction. In anexemplary embodiment, the reagents are copper(II) oxide and potassiumiodide. (Both need to be present for the reaction to work.) In oneembodiment, the contacting step is performed in the presence of asolvent. Exemplary solvents include, for example, alkanols. Exemplaryalkanols include, for example, methanol. In one aspect, the process iscarried out at reflux. In one embodiment, the reaction is conductedunder an inert atmosphere of nitrogen, argon, or a combination thereof.

Accordingly, provided are methods for preparing derivatized3,4-alkylenedioxythiophene compounds comprising contacting a3,4-alkylenedioxythiophene with a halo-1,2-alkanediol in the presence ofan acid to form a compound of Formula II

wherein X is halogen and n is from 1 to 4; and subsequently contacting acompound of Formula II with an inorganic hydroxide, alkali metalcarboxylate, alkaline earth metal carboxylate, ammonium or alkylammoniumcarboxylate, alkali metal alkoxide, alkaline earth metal alkoxide,ammonium or alkylammonium alkoxide, to form a compound of Formula I:

In one aspect, the derivatized 3,4-alkylenedioxythiophene is prepared bycontacting a 3,4-dihalothiophene with an alkoxide in the presence ofcopper and iodine reagents.

In one embodiment, provided are methods for preparing EDOT-CH₂OHcomprising contacting 3,4-dialkoxythiophene with 3-halo-1,2-propanediolin the presence of an acid to form a compound of Formula IV:

wherein X is halogen; and subsequently contacting a compound of FormulaIV with an inorganic hydroxide, ammonium or alkylammonium hydroxide,alkali metal carboxylate, alkaline earth metal carboxylate, ammonium oralkylammonium carboxylate, alkali metal alkoxide, alkaline earth metalalkoxide, ammonium or alkylammonium alkoxides, to form EDOT-CH₂OH. Inone embodiment, the 3,4-dialkoxythiophene is prepared by contacting a3,4-dihalothiophene with an alkoxide in the presence of copper andiodine containing reagents.

Also provided are compounds of Formula IV

wherein X is halogen.

Also provided are compounds of Formulas I, II, III, IV, V, and VIprepared by the processes described herein.

A representative synthetic scheme of the present invention is providedbelow as Scheme I. Scheme 1 demonstrates exemplary processes for thepreparation of EDOT-CH₂OH((2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)-methanol). The skilledpractitioner will know how to make use of variants of these processsteps. In this representative scheme, treatment of 3,4-dihalothiophenewith an alkoxide base in the presence of copper(II) oxide and potassiumiodide provides the corresponding 3,4-alkylenedioxythiophene. Reactionof 3,4-dialkoxythiophene with 3-halo-1,2-propanediol in the presence ofan acid, such as para-toluenesulfonic acid, or the like, gives rise to ahalomethyl derivatized EDOT. Subsequent reaction of the halo derivativewith, for example, an alkali metal hydroxide, alkaline earth metalhydroxide, ammonium or alkylammonium hydroxide, alkali metalcarboxylate, alkaline earth metal carboxylate, ammonium or alkylammoniumcarboxylate, alkali metal alkoxide, alkaline earth metal alkoxide, orammonium or alkylammonium alkoxide converts the halo-EDOT tohydroxy-EDOT.

Compounds having Formulae V and VI can be prepared in a manner analogousto that for Compounds having Formula I and II, respectively. Compoundshaving Formula I or Formula V are referred to collectively as“derivatized 3,4-alkylenedioxythiophene compounds”.

Also provided are compositions comprising derivatized3,4-alkylenedioxythiophene compounds made by the processes describedherein. These compositions can be in any form, including, but notlimited to solutions, emulsions, colloids, and dispersions. In oneaspect, the derivatized 3,4-alkylenedioxythiophene compounds areprepared using a synthetic scheme described herein

Also provided are devices comprising derivatized3,4-alkylenedioxythiophene compounds, such as EDOT-CH₂OH. In oneembodiment, a device is provided that has at least one layer comprisingat least one polymer comprising at least one monomer made by theprocesses described herein. In on embodiment, the device will furthercomprise at least one dispersion liquid, and optionally a processingaid, charge transporting material, or charge blocking material. Thedevice can be, for example, for converting electrical energy intoradiation, for detecting signals through electronic processes, or forconverting radiation into electrical energy. In one aspect, the devicewill include one or more electronic components that include one or moreorganic semiconductor layers. In some exemplary embodiments, the devicewill further comprise coating materials for memory storage devices,antistatic films, biosensors, electrochromic devices, solid electrolytecapacitors, energy storage devices such as a rechargeable battery,electromagnetic shielding applications or combinations thereof.

As described in published application U.S. 2004/0254297 and copendingU.S. Provisional Application No. 60/694,276, each of which is hereinincorporated by reference in its entirety,poly(3,4-ethylenedioxythiophene)/fluorinated acid polymer (“PEDOT/FAP”),is an electrically conducting polymer (ECP) and is made bypolymerization of 3,4-ethylenedioxythiophene (EDOT) in water and afluorinated acid polymer. The fluorinated acid polymer can be anypolymer which is fluorinated, and has acidic groups. Exemplary acidicgroups include, for example, carboxylic acid groups, sulfonic acidgroups, sulfonimide groups, phosphoric acid groups, phosphonic acidgroups, or combinations thereof. The fluorinated acid polymer can beeither soluble, or exist as a colloid in an aqueous media. An aqueousmedia refers to a mixture of liquid that has at least 40% water.

Electrically conducting polymer (ECP) of PEDOT/FAP has multipleutilities, including use as a buffer layer or hole-injection layer inorganic electronic devices. Use of PEDOT/FAP in organic light emittingdiodes has provided improved lifetime and efficiency for the devices.EDOT-CH₂OH as prepared by the methods of the present invention can beused in place of EDOT to make PEDOT/FAP. The term of buffer layer orhole-injection layer refers to a material which is coated on an anode tofacilitate hole injection from anode and hole transport through thelayer.

Accordingly, in one embodiment, provided are methods of makingelectrically conductive polymers comprising a step of polymerizingEDOT-CH₂OH or another derivatized 3,4-alkylenedioxythiophene compounddescribed herein in an aqueous FAP solution or dispersion. In one aspectof the invention, the electrically conductive polymers can comprisecopolymers of EDOT-CH₂OH with at least one comonomer. The copolymer canbe, for example, a block copolymer, a gradient copolymer, or a randomcopolymer. Examples of comonomers include, but are not limited to anyoxidative polymerizable monomer such as pyrroles, anilines, thiophenes,substituted pyrroles, substituted anilines, substituted thiophenes, orcombinations thereof.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms followed by the Illustrative Electronic Devices,and finally Examples.

1. DEFINITIONS AND CLARIFICATION OF TERMS

Before addressing details of embodiments described below, some terms aredefined or clarified.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of “a” or “an” are employed to describe elements andcomponents of the invention. This is done merely for convenience and togive a general sense of the invention. This description should be readto include one or at least one and the singular also includes the pluralunless it is obvious that it is meant otherwise.

The term “halogen” or “halo” refers to chlorine, bromine, fluorine, andiodine.

The term “organic electronic device” is intended to mean a deviceincluding one or more semiconductor layers or materials. Organicelectronic devices include, but are not limited to: (1) devices thatconvert electrical energy into radiation (e.g., a light-emitting diode,light emitting diode display, diode laser, or lighting panel), (2)devices that detect signals through electronic processes (e.g.,photodetectors photoconductive cells, photoresistors, photoswitches,phototransistors, phototubes, infrared (“IR”) detectors, or biosensors),(3) devices that convert radiation into electrical energy (e.g., aphotovoltaic device or solar cell), and (4) devices that include one ormore electronic components that include one or more organicsemiconductor layers (e.g., a transistor or diode).

The term “device” also includes coating materials for memory storagedevices, antistatic films, biosensors, electrochromic devices, solidelectrolyte capacitors, energy storage devices such as a rechargeablebattery, and electromagnetic shielding applications.

The term “layer” is used interchangeably with the term “film” and refersto a coating covering a desired area. The area can be as large as anentire device or a specific functional area such as the actual visualdisplay, or as small as a single sub-pixel. Films can be formed by anyconventional deposition technique, including vapor deposition and liquiddeposition. Liquid deposition techniques include, but are not limitedto, continuous deposition techniques such as spin coating, gravurecoating, curtain coating, dip coating, slot-die coating, spray-coating,and continuous nozzle coating; and discontinuous deposition techniquessuch as ink jet printing, gravure printing, and screen printing.

The term “active” when referring to a layer or material is intended tomean a layer or material that exhibits electronic or electro-radiativeproperties. An active layer material may emit radiation or exhibit achange in concentration of electron-hole pairs when receiving radiation.

“Aralkane” refers to a moiety composed of an alkane bearing an arylsubstituent or to a cycloalkane fused to an aryl ring and having fromabout 6 to about 20 carbon atoms (and all combinations andsubcombinations of ranges and specific numbers of carbon atoms therein),with from about 6 to about 10 carbon atoms being preferred. Non-limitingexamples include, for example, toluene, ethyl benzene, mesitylene,tetralin, cumene, cymene, methylnaphthalene, and diphenylmethane.

The term “colloid” or “colloidal” refers to the minute particlessuspended in a continuous liquid medium, said particles having ananometer-scale particle size. The term “colloid-forming” refers tosubstances that form minute particles when dispersed in a liquid medium,i.e., “colloid-forming” materials are not soluble in the liquid medium.

“Alkyl” refers to an optionally substituted, saturated straight,branched, or cyclic hydrocarbon radical having from about 1 to about 20carbon atoms (and all combinations and subcombinations of ranges andspecific numbers of carbon atoms therein). Alkyl groups include, but arenot limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl,3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl.

“Alkoxide” refers to an alkyl-O— anion, wherein alkyl is as previouslydefined. Alkoxide is generally associated with a cationic counterion,such as Na+, K+, Li+, Mg++, Ca++, ammonium, alkylammonium, and the likeon an equivalent charge basis. Exemplary alkoxides include, for example,methoxide, ethoxide, n-propoxide, i-propoxide, n-butoxide, andheptoxide.

“Alkanol” refers to alkyl alcohols, such as those provided byprotonation of alkoxides, wherein alkyl is as previously defined.

“Halo” refers to a fluoro, chloro, bromo, or iodo moiety.

As used herein, the term “electrically conductive polymer” refers to anypolymer or oligomer which is inherently or intrinsically capable ofelectrical conductivity without the addition of carbon black orconductive metal particles. The term “polymer” encompasses homopolymersand copolymers. The term “electrical conductivity” includes conductiveand semi-conductive. In one embodiment, films made from the dopedelectrically conductive polymer have a conductivity of at least 10⁻⁷S/cm

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductive memberarts.

2. ILLUSTRATIVE ELECTRONIC DEVICES

One illustration of an organic electronic device structure is shown inFIG. 1. The device 100 has an anode layer 110 and a cathode layer 160,and a photoactive layer 130 between them. Adjacent to the anode is alayer 120 comprising a hole injection layer derived from an electricallyconducting polymer, for example, poly(EDOT-CH₂OH)/FAP of this invention.Optionally, a hole transporting layer (not shown in FIG. 1) issandwiched between a hole injection layer 120 and a photoactive layer130. Adjacent to the cathode is an electron transport layer 140comprising an electron transport material. As an option, devices may usea further electron injection layer 150, next to the cathode.

The device 100 can include a substrate 105. The substrate 105 may berigid or flexible, for example, glass, ceramic, metal, or plastic. Whenvoltage is applied, emitted light is visible through the substrate 105.The anode layer 110 may be deposited on the substrate 105.

As used herein, the term, the charge injection refers to a material thatfacilitates hole injection from anode or electron injection fromcathode.

As used herein, the term “photoactive” refers to a material that emitslight when activated by an applied voltage (such as in a light-emittingdiode or light-emitting electrochemical cell), or responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). An example of a photoactive layer is anemitter layer.

As used herein, the term “charge transport,” when referring to a layer,material, member or structure, is intended to mean such layer, material,member or structure facilitates migration of such charge through thethickness of such layer, material, member, or structure with relativeefficiency and small loss of charge, and is meant to be broad enough toinclude materials that may act as a hole transport or an electrontransport material. The term “electron transport” or “hole transport”when referring to a layer, material, member or structure means such alayer or material, member or structure that promotes or facilitatesmigration of negative charge or positive charge, respectively, throughsuch a layer or material into another layer, material, member orstructure.

The term “charge blocking,” when referring to a layer, material, member,or structure, is intended to mean such layer, material, member orstructure reduces the likelihood that a charge migrates into anotherlayer, material, member or structure. The term “electron blocking” whenreferring to a layer, material, member or structure is intended to meansuch layer, material, member or structure that reduces that likelihoodthat electrons migrate into another layer, material, member orstructure.

Depending upon the application of the device 100, the photoactive layer130 can be a light-emitting layer that is activated by an appliedvoltage (such as in a light-emitting diode or light-emittingelectrochemical cell), a layer of material that responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). Examples of photodetectors includephotoconductive cells, photoresistors, photoswitches, phototransistors,and phototubes, and photovoltaic cells, as these terms are described inKirk-Othmer Concise Encyclopedia of Chemical Technology, 4^(th) edition,p. 1537, (1999).

In certain embodiments, a charge transport layer, for example, theelectron transport layer 140 comprises, but are not limited to, metalchelated oxinoid compounds, such asbis(2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(III)(BAlQ), tetra(8-hydroxyquinolato)zirconium (ZrQ), andtris(8-hydroxyquinolato)aluminum (Alq₃); azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD),3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthroline derivativessuch as 9,10-diphenylphenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and any one ormore combinations thereof. The optional electron injection layer 150 maybe inorganic and comprise BaO, LiF, Li₂O, or the like.

In certain embodiments, the photoactive layer 130 comprises aphotoactive material admixed with at least onetris(N-aryl-benzimidazole)benzene compound.

The other layers in the device can be made of any materials which areknown to be useful in such layers. The anode 110, is an electrode thatis particularly efficient for injecting positive charge carriers. It canbe made of, for example materials containing a metal, mixed metal,alloy, metal oxide or mixed-metal oxide, or it can be a conductingpolymer, and mixtures thereof. Suitable metals include the Group 11metals, the metals in Groups 4, 5, and 6, and the Group 8-10 transitionmetals. If the anode is to be light-transmitting, mixed-metal oxides ofGroups 12, 13 and 14 metals, such as indium-tin-oxide, are generallyused. The anode 110 may also comprise an organic material such aspolyaniline as described in “Flexible light-emitting diodes made fromsoluble conducting polymer,” Nature vol. 357, pp 477 479 (11 Jun. 1992).At least one of the anode and cathode should be at least partiallytransparent to allow the generated light to be observed.

The optional hole transport layer, which is layer that facilitates themigration of positive charges through the layer into another layer ofthe electronic device, can include any number of materials. Examples ofother hole transport materials have been summarized for example, in KirkOthmer Encyclopedia of Chemical Technology, Fourth Edition, Vol. 18, p.837 860, 1996, by Y. Wang. Both hole transporting molecules and polymerscan be used. Commonly used hole transporting molecules include, but arenot limited to:N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),a-phenyl 4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA), bis[4(N,N-diethylamino)-2-methylphenyl] (4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),N,N,N′,N′ tetrakis-(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB), andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers include, but are not limited to,polyvinylcarbazole, (phenylmethyl)polysilane, polydioxythiophenes,polypyrroles, and polyanilines. It is also possible to obtain holetransporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate.

In another embodiment, HTM comprises copolymer of arylamines withconjugated monomers. In another embodiment, the HTM polymers orcopolymers comprises crosslinkable segments to render insolubility inthe solvents of subsequent layer depositions. It is also possible toobtain hole transporting polymers by doping hole transporting moleculessuch as those mentioned above into polymers such as polystyrene andpolycarbonate.

Any organic electroluminescent (“EL”) material can be used as thephotoactive material in layer 130. Such materials include, but are notlimited to, small organic fluorescent compounds, fluorescent andphosphorescent metal complexes, conjugated polymers, and mixturesthereof. Examples of fluorescent compounds include, but are not limitedto, pyrene, perylene, rubrene, coumarin, derivatives thereof, andmixtures thereof. Examples of metal complexes include, but are notlimited to, metal chelated oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq3); cyclometalated iridium andplatinum electroluminescent compounds, and mixtures thereof. Examples ofconjugated polymers include, but are not limited topoly(phenylenevinylenes), polyfluorenes, poly(spirobifluorenes),polythiophenes, poly(p-phenylenes), copolymers thereof, and mixturesthereof.

In one embodiment of the device, the photoactive material is anorganometallic complex. In one embodiment, the photoactive material is acyclometalated complex of iridium or platinum. Complexes of iridium withphenylpyridine, phenylquinoline, or phenylpyrimidine ligands have beendisclosed as electroluminescent compounds in Petrov et al., PublishedPCT Application WO 02/02714. Other organometallic complexes have beendescribed in, for example, published applications US 2001/0019782, EP1191612, WO 02/15645, and EP 1191614. Electroluminescent devices with anactive layer of polyvinyl carbazole (PVK) doped with metallic complexesof iridium have been described by Burrows and Thompson in published PCTapplications WO 00/70655 and WO 01/41512. Electroluminescent emissivelayers comprising a charge carrying host material and a phosphorescentplatinum complex have been described by Thompson et al., in U.S. Pat.No. 6,303,238, Bradley et al., in Synth. Met. (2001), 116 (1-3),379-383, and Campbell et al., in Phys. Rev. B, Vol. 65 085210. Analogoustetradentate platinum complexes can also be used. Theseelectroluminescent complexes can be used alone, or doped intocharge-carrying hosts, as noted above. In one embodiment, the compoundsare charge-carrying hosts admixed with other fluorescent orphosphorescent materials.

Examples of electron transport materials which can be used in theelectron transport layer 140 may include at least onetris(N-aryl-benzimidazole)benzene compounds. These layers can optionallyinclude a polymer, such as a polyfluorene or a polythiophene. Othersuitable materials for layer 140 include metal chelated oxinoidcompounds, such as tris(8-hydroxyquinolato)aluminum (AlQ₃); and azolecompounds such as 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole(PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(TAZ), and 1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxalinederivatives such as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthrolinessuch as 4,7-diphenyl-1,10-phenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and mixturesthereof. The optional electron injection layer 150 may be inorganic andcomprise BaO, LiF, Li₂O, or the like.

The cathode 160, is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used. Li-containing organometalliccompounds, LiF, and Li₂O can also be deposited between the organic layerand the cathode layer to lower the operating voltage.

An encapsulation layer 170 may be deposited over layer 160 to prevententry of undesirable components, such as water and oxygen, into thedevice 100. Such components can have a deleterious effect on the organiccomponents. In one embodiment, the encapsulation layer 170 is a barrierlayer or film.

It is known to have other layers in organic electronic devices. Forexample, there can be a layer (not shown) between the anode 110 and holeinjection layer 120 to facilitate positive charge transport and/orband-gap matching of the layers, or to function as a protective layer.Layers that are known in the art can be used. In addition, any of theabove-described layers can be made of two or more layers. Alternatively,some or all of anode layer 110, the hole injection layer 120, theelectron transport layer 140 and optional electron injection layer 150,and cathode layer 160, may be surface treated to increase charge carriertransport efficiency. The choice of materials for each of the componentlayers is preferably determined by balancing the goals of providing adevice with high device efficiency with device operational lifetime.

The device can be prepared by a variety of techniques, includingsequentially depositing the individual layers on a suitable substrate.Substrates such as glass, metal, and polymeric films can be used.Conventional vapor deposition techniques can be used, such as thermalevaporation, chemical vapor deposition, and the like. Alternatively, theorganic layers can be applied by liquid deposition using suitablesolvents. The liquid can be in the form of solutions, dispersions, oremulsions. Typical liquid deposition techniques include, but are notlimited to, continuous deposition techniques such as spin coating,gravure coating, curtain coating, dip coating, slot-die coating,spray-coating, and continuous nozzle coating; and discontinuousdeposition techniques such as ink jet printing, gravure printing, andscreen printing, any conventional coating or printing technique,including but not limited to spin-coating, dip-coating, roll-to-rolltechniques, ink jet printing, screen-printing, gravure printing and thelike.

In one embodiment, the different layers have the following range ofthicknesses: anode 110, 500-5000 Å, in one embodiment 1000-2000 Å; holeinjection layer 120, 50-2000 Å, in one embodiment 200-1000 Å;photoactive layer 130, 10-2000 Å, in one embodiment 100-1000 Å; layers140 and 150, 50-2000 Å, in one embodiment 100-1000 Å; cathode 160,200-10000 Å, in one embodiment 300-5000 Å. The location of theelectron-hole recombination zone in the device, and thus the emissionspectrum of the device, can be affected by the relative thickness ofeach layer. Thus the thickness of the electron-transport layer should bechosen so that the electron-hole recombination zone is in thelight-emitting layer. The desired ratio of layer thicknesses will dependon the exact nature of the materials used.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described below. All publications,patent applications, patents, and other references mentioned herein areincorporated by reference in their entirety and for all purposes.

EXAMPLES

Example A provides a method for the prior art method of synthesizingEDOT-CH₂OH for comparative purposes. Examples 1 through 13 providerepresentative methods of the present invention.

Example A

Synthesis of 3,4-ethylenedioxythiophene methanol is adapted from thepublication “Electropolymerization of and 3,4-ethylenedioxythiophenemethanol in the presence of dodecylbenzenesulfonate”, Lima A, SchottlandP, Sadki A, Chevrot C; Synth. Met. 1998, 93, 33-41.

1) Synthesis of Diethyl Thiodiglycolate

In a 2-necked round bottom flask equipped with a reflux condenser and anequilibrium addition funnel 100 g (0.667 mol) thiodiglycolic acid wasdissolved in 500 mL refluxing ethanol. The equilibrium addition funnelwas charged with 40 mL concentrated sulfuric acid. The acid was addeddropwise and the reaction refluxed overnight. Upon cooling the reactionto room temperature it was carefully poured into 600 mL water. Theproduct was extracted with diethyl ether until the ether wash no longercontained the desired product. The organic extracts were washed with asaturated sodium bicarbonate solution three times. Upon drying withmagnesium sulfate and solvent removal under reduced pressure a colorlessoil was isolated (131.3 g, 95% yield). Structure and purity wereconfirmed by ¹H/¹³C NMR and GC-MS.

2) Synthesis of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate

In a 2 L two-necked flask equipped with a reflux condenser 175 g (2.57mol) of sodium ethoxide was dissolved in 1200 mL anhydrous ethanol. Thereaction was cooled to 0 C and a solution of 106 g (0.514 mol)diethylthioglycolate and 188 g (1.28 mol) diethyl oxalate in ethanol wasadded dropwise. Upon completion of the addition, the cooling bath wasremoved and the reaction heated to reflux overnight. The reaction wasthen cooled to room temperature and filtered. The resulting yellow solidwas washed with ethanol and allowed to dry. The solid was split into twoportions and each was added to a large Erlenmeyer flask with water tomake a suspension upon stirring. Acidification with HCl provided a whitesolid. The solid was filtered and allowed to dry under vacuum to give 80g (60% yield) of product as a white powder. Further material can beisolated by cooling the mother liquor and subsequent filtration.Structure and purity were confirmed by ¹H/¹³C NMR and LC-MS.

3) Synthesis of diethyl2,3-dihydro-2-(hydroxymethyl)thieno[3,4-b][1,4]dioxine-5,7-dicarboxylate

7.7 mL (0.0902 mol) of epibromohydrin and 1.92 g (0.0139 mol) ofpotassium carbonate were dissolved in 100 mL water and added to arefluxing mixture of 16.11 g (0.0694 mol) diethyl3,4-dihydroxythiophene-2,5-dicarboxylate in 350 mL ethanol. Afterheating to reflux for 1 hour, an additional 5.3 mL (0.0624 mol)epibromohydrin was added and the reaction heated to reflux overnight.Upon cooling to room temperature the reaction was concentrated byevaporation and then poured into 500 ml water. The mixture was acidifiedand then extracted with methylene chloride until the organic wash nolonger indicated product was present. The organic fractions were washedwith saturated brine then dried with magnesium sulfate. The solvent wasremoved under reduced pressure to give a yellow solid. Columnchromatography was performed using 60% ethyl acetate in hexane to give a70:30 mixture of the product and propylene isomer in 55% yield as awhite solid. Structure and purity were confirmed by ¹H/¹³C NMR andLC-MS.

4) Synthesis ofdiethyl-2-(hydroxymethyl)-2,3-dihydrothieno[3,4-b]-1,4-dioxine-5,7-dicarboxylicacid

In a 500 mL round bottom flask equipped with a reflux condenser 11.3 g(0.0357 mol) diethyl2,3-dihydro-2-(hydroxymethyl)thieno[3,4-b][1,4]dioxine-5,7-dicarboxylatewas combined with 12.0 g (0.214 mol) potassium hydroxide in 250 mLwater. The reaction mixture was refluxed and the progress of thereaction tracked by TLC. Upon completion of the hydrolysis the reactionwas concentrated to ˜100 mL. The mixture was cooled to 0 C thenacidified with concentrated HCl. After allowing to warm to roomtemperature overnight the white solid was filtered and washed with asmall amount of water. Drying under high vacuum gave 8.5 g (90%) ofproduct as a white solid. Structure and purity were confirmed by ¹H/¹³CNMR and LC-MS.

5) Synthesis ofdiethyl-2-(hydroxymethyl)-2,3-dihydrothieno[3,4-b]-1,4-dioxin-2-ylmethanol

In a 100 mL round bottom flask, 14.0 g (0.053 mol) of finely powdered2,3-dihydro-2-(hydroxymethyl)thieno[3,4-b]dioxine-5,7-dicarboxylic acid,0.42 g copper(II) oxide, and 25 mL quinoline were combined. A refluxcondenser was equipped and reaction flask purged with nitrogen. Themixture was heated to 225 C and the reaction traced by TLC. Once allstarting material was consumed, the reaction was cooled to roomtemperature, diluted with ether and filtered. The ether was removedunder reduced pressure. The crude product mixture was purified by columnchromatography using 30% ethyl acetate in hexane. Upon removal of thesolvent 4.4 g (48% yield) of a light yellow oil was isolated. Structureand purity were confirmed by ¹H/¹³C NMR and GC-MS.

Example 1 Synthesis of Chloromethyl-3,4-ethylenedioxythiophene forconversion to EDOT-MeOH 1) 3,4-dimethoxythiophene synthesis from3,4-dibromothiophene for the improved EDOT-MeOH synthesis

Sodium methoxide was prepared by slow addition of small cubes of sodiummetal (25 g, 1.05 mol) to ice bath cooled anhydrous methanol (600 mL) ina 1 L 3-necked flask equipped with a reflux condenser under a nitrogenblanket. Between additions of the sodium it was covered in kerosene toexclude moisture. After complete dissolution of the sodium, 50 g (0.207mol) of 3,4-dibromothiophene, 16.5 g (0.207 mol) copper (II) oxide, and1.37 g (0.00827 mol) potassium iodide was added to the reaction mixture.The reaction was refluxed for three days. The reaction was then cooledto room temperature and filtered through a sintered glass frittedfunnel. The resulting solid was rinsed with ether and the filtrate waspoured into 500 mL water. The solution was then extracted with ether.The organic fractions were combined and dried with magnesium sulfate.Solvent removal gave a light yellow oil. Vacuum distillation gave 26.2 gof a clear, colorless oil whose structure and purity were confirmed by¹H and ¹³C NMR and GC-MS. Yield was 88% of theoretical.

2) Synthesis of 2-(chloromethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine

Under a nitrogen atmosphere in a 500 mL round bottom flask equipped witha reflux condenser, 20.0 g (0.139 mol) dimethoxythiophene, 17.8 g (0.161mol) 3-chloro-1,2-propanediol, and 5 g p-toluenesulfonic acid wasdissolved in 350 mL toluene. The reaction was then heated to ˜90 Covernight. At this time TLC indicated consumption of starting material.After cooling the reaction mixture was concentrated to ˜100 mL andpoured into saturated potassium carbonate solution. The mixture wasextracted with DCM and the combined extracts were dried with magnesiumsulfate. Solvent removal gave a dark oil that was purified by columnchromatography using 3:1 hexanes/DCM. Solvent removal gave the productas a white solid. Structure and purity were confirmed by ¹H/¹³C NMR andLC-MS.

Example 2 Conversion of 3,4-dimethoxythiophene to2-(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine

Under nitrogen, 20.0 g (0.139 mol) dimethoxythiophene, 25.0 g (0.161mol) 3-bromo-1,2-propanediol, and 5 g p-toluenesulfonic acid wascombined with 350 mL toluene in a 500 mL round bottom flask equippedwith a reflux condenser and stir bar. The reaction mixture was spargedwith nitrogen for 30 minutes then heated to 100 C overnight. Uponcooling to room temperature the reaction mixture was concentrated to˜100 mL and poured into saturated potassium carbonate solution. Theresulting solution was extracted with DCM. The combined extracts werewashed with brine, then dried with magnesium sulfate. Solvent removalgave a black oil. The crude material was purified by columnchromatography using 3:1 hexanes/DCM. Solvent removal gave a white solidthat was dried under high vacuum overnight to give 18.6 g of material.The structure and purity were confirmed by ¹H/¹³C NMR and GC-MS. Yieldwas 57% of theoretical.

Example 3 Synthesis of(2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methanol from(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methyl acetate 1) Synthesis of(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methyl acetate (EDOT-MeOAc)

In a 50 mL Schlenk tube 1.00 g of to2-(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine was combined with0.5 g (0.0051 mol) potassium acetate and 25 mL DMSO. The tube was sealedand stirred for 1 h at 100 C. At this time TLC indicated completeconsumption of starting material. The reaction was poured into water andextracted with ether. After removing the ether under reduced pressurecolumn chromatography was performed using 90% methylene chloride inhexane to isolate a light yellow oil in 90% yield. The structure andpurity were confirmed by ¹H/¹³C NMR and GC-MS.

2) Synthesis of (2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methanol(EDOT-MeOH)

In a 25 mL round bottom flask equipped with a reflux condenser 0.64 g(0.0030 mol) of (2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methyl acetatewas combined with 50% NaOH in water. The reaction was refluxed overnightand then cooled to room temperature. It was then poured into anErlenmeyer flask filled with 100 mL water. The mixture was acidifiedthen extracted with DCM. The solvent was removed under reduced pressureand column chromatography (7:3 hexanes/ethyl acetate) was performed togive 0.46 g (90%) of product. The structure was confirmed by LC-MS and¹H/¹³C NMR.

Example 4 Synthesis of EDOT-MeOH from EDOT-Methyl-Benzoate 1) Synthesisof (2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methyl benzoate

In a 100 mL round bottom flask 9.00 g (0.0382 mol)2-(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine, 6.39 g (0.0459mol) ammonium benzoate, and 55 g DMSO were combined. A reflux condenserwas equipped and the reaction was heated to 100 C overnight. Aftercooling to room temperature, the reaction mixture was poured into waterand the product was extracted with methylene chloride. The organicfractions were combined and the solvent removed under reduced pressure.Purification by column chromatography provided 7.5 g (71% yield) of awhite solid whose structure was confirmed by 1H/¹³C NMR and LC-MS.

2) Synthesis of (2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methanol

In a 100 mL round bottom flask, 7.5 g (0.027 mol)(2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methyl benzoate was dissolvedin a minimal amount of warm ethanol and dropwise added to a refluxingsolution of 4.58 g (0.081 mol) potassium hydroxide in 50 mL water. Afterheating overnight, the reaction was cooled to room temperature andacidified to pH 7 by dropwise addition of concentrated hydrochloricacid. The reaction mixture was extracted with methylene chloride. Theorganic fractions were combined and the solvent removed under reducedpressure. Purification by column chromatography provided 3.95 g (85%yield) of (2,3-dihydrothieno[3,4-b][1,4]dioxin-3-yl)methanol. Structurewas confirmed by 1H/¹³C NMR and LC-MS.

Example 5 Synthesis of EDOT-MeOH from Chloromethyl-EDOT From aCarboxylic Acid Salt to Form an Ester and Subsequent Cleaving of theEster Linkage with Potassium Hydroxide

Chloromethyl-EDOT will be reacted with a carboxylic acid salt, e.g.Acetate, heated to 100-140° C. in a polar/aprotic solvent, e.g. DMF,DMAc or DMSO. The resulting ester will then be cleaved easily by using atypical base saponification, e.g. 1% KOH in MeOH/H₂O or withtransesterification using an Acid or a base in the presence of MeOH.

Example 6 Synthesis of EDOT-MeOH from Chloromethyl-EDOT Using Alkoxidesand Subsequent Cleaving of the Ether Linkage Formed

Sodium or sodium hydride will be used to form the alkoxide of any of thefollowing alcohols:

Chloromethyl-EDOT will then be reacted with the alkoxide to yield theether. These ether functionalities will then be easily cleaved by usingthe well-documented appropriate agent, yielding EDOT-MeOH.

Example 7 Synthesis of EDOT-MeOH from Bromomethyl-EDOT In SituGeneration of Iodomethyl-EDOT to be Reacted with KOH

In a round bottom flask, 1 g Bromomethyl-EDOT will be dissolved inacetone. A catalytic amount of sodium iodide will then be added. SolidKOH would then be added along with a small portion of DI Water. Theresulting precipitate should be KCl, yielding the desired product.

Example 8 Synthesis of EDOT-MeOH from Bromomethyl-EDOT Direct Reactionwith KOH

Bromomethyl-EDOT will be dissolved in a polar organic and then subjectedto nucleophilic attack by OH⁻. Isolation would involve water extractionand other standard practices.

Example 9 Synthesis of EDOT-MeOH from Bromomethyl-EDOT Direct Reactionwith Alkali Metal Hydroxide, e.g. KOH, with a Catalytic Amount ofAppropriate Crown Ether, e.g. 18-Crown-6

Bromomethyl-EDOT will be susceptible to nucleophilic attack with no“pre-derivitization” required. This compound would be dissolved in apolar organic and then subjected to nucleophilic attack by OH⁻ in thepresence of a catalytic amount of the proper crown ether, e.g. if usingNaOH, 15-Crown-5 would be used. Isolation will involve water extractionand other standard practices.

Example 10 Solubility Comparison Between EDOT-MeOH and EDOT

EDOT (2,3,-dihydrothieno[3,4-b]-1,4-dioxin) monomer purchased fromAldrich Advance Science Company (Milwaukee, USA) and EDOT-MeOH made inExample 5 were tested for solubility in water at room temperature whichis about 23° C. EDOT has solubility less than 0.4% (w/w), but EDOT-MeOHhas solubility of 1.4% (w/w). The improvement is more than sufficient tofacilitate polymerization at the concentration illustrated in Example11.

Example 11 Illustration of EDOT-MeOH Polymerization in the Presence ofNafion®, a Perfluoroethylene-Ether-Sulfonic Acid, and Use of theElectrically Conducting for OLEDs 1) Polymerization of EDOT-MeOH in thepresence of Nafion®, poly(tetrafluoroethylene)/perfluoroethersulfonicacid

The Nafion® dispersion at 25% (w/w) having EW1050 was made using aprocedure similar to the procedure in U.S. Pat. No. 6,150,426, Example1, Part 2, except that the temperature was approximately 270° C. It wasthen diluted with water to form a 13.2% (w/w) dispersion for thepolymerization. EDOT-MeOH used in this example was made according to theprocedure in Example 5.

In a 500 mL reaction kettle were put 57.4 g of 13.2% solid contentaqueous Nafion® dispersion (7.23 mmol SO₃H groups), 99.0 g water, and130 μL of 37% HCl (1.62 mmol). While the mixture was stirred at 200 RPMusing an overhead stirrer fitted with a double stage propeller blade, astock solution of 0.65% iron(III)sulfate in water was made and 2.1 μg ofthe solution was added to the kettle. To the mixture, 10.8 g (3.318mmol) sodium persulfate pre-dissolved in 10 g water, and 0.548 g (3.184mmol) EDOT-MeOH pre-dissolved in 35 g water were added. The addition wasstarted from separate syringes using addition rate of 0.71 mL/h forNa₂S₂O₈/water and 2.5 mL/h for EDOT-MeOH water while continuouslystirring at 200 RPM. The addition was accomplished by placing eachsolution in a syringe connected to a Teflon® tube. The end of theTeflon® tube was placed above the reaction mixture such that theinjection involved individual drops falling from the end of the tubesuch that the injection was gradual. Once addition was complete, thereaction mixture was allowed to proceed for another 14.5 hours beforetermination by adding 15 g Lewatit® S100 (a trade name from Bayer,Pittsburgh, Pa., for sodium sulfonate of crosslinked polystyrene) and 15g Lewatit® MP62 WS (a trade from Bayer Company, Pittsburgh, Pa., forfree base/chloride of tertiary/quaternary amine of crosslinkedpolystyrene). The two resins were washed first before use with deionizedwater separately until there was no color in the water. The resintreatment was allowed to proceed for 11.5 hrs while being stirred at 120RPM. The resulting slurry was then suction-filtered through a Whatman #4filter paper. The poly(EDOT-MeOH)/Nafion® dispersion is blue in color,which is the typical color for having electrical conductivity. Thedispersion is stable and has pH of 4.2 and solid percentage was measuredto be 3.92% (w/w). Electrical conductivity of thin films cast from thedispersion and baked in air at 130° C. for 10 minutes is measured to be1.3×10⁻² S/cm at room temperature.

2) Use of Poly(EDOT-MeOH)/Nafion® as a Hole Injection Layer (HIL) forFabrication of Organic Light Emitting Diodes (OLEDs) Using PolymericGreen Emitter and Diode Performance

The Poly(EDOT-MeOH)/Nafion® dispersion made in section 1 of Example 11was spin-coated on glass/ITO backlight substrates (30 mm×30 mm). EachITO substrate having ITO thickness of 100 to 150 nm consists of 3 piecesof 5 mm×5 mm pixels and 1 piece of 2 mm×2 mm pixel for light emission.Once spin-coated on ITO substrates, the films were baked first at 130°C. in air for 10 minutes and then at 200° C. for 10 minutes. Thethickness of the layer after baked was 185 nm. ThePoly(EDOT-MeOH)/Nafion® layer was top-coated with approximately 74 nmthick film of Lumination Green 1303 electroluminescence polymer from DowChemicals (from 1% w/v solution in p-Xylene) in air. Following thebaking of the electroluminescent film at 130° C. in a dry box for 30minutes, a cathode consisting of 3 nm of Ba and 250 nm of Al wasthermally evaporated at pressure less then 4×10⁻⁶ Torr. Encapsulation ofthe devices was achieved by bonding a glass slide on the back of thedevices using an UV-curable epoxy resin.

Table 1 shows light emitting device efficiency 200, 500, 1,000 and 2,000nits (cd/m²). The data shows that efficiency rises very rapidly at lowluminance and is about the same from 200 cd/m² to 2,000 cd/m².

TABLE 1 Lumination Green 1303 Device Efficiency 200 (cd/m²) 500 (cd/m²)1,000 (cd/m²) 2,000 (cd/m²) Efficiency 9.9 ± 3.4 10.2 ± 4.2 10.2 ± 4.110.4 ± 3.6 (cd/A)

1. A process for preparing a compound of Formula I:

comprising contacting a compound of Formula II:

wherein n is from 1 to 4 and X is halogen; with an inorganic hydroxide,alkali metal carboxylate, alkaline earth metal carboxylate, ammoniumcarboxylate, alkylammonium carboxylate, alkali metal alkoxide, alkalineearth metal alkoxide, ammonium metal alkoxide, or alkylammonium metalalkoxide.
 2. The process of claim 1 wherein the inorganic hydroxide isan alkali metal hydroxide, alkaline earth metal hydroxide, ammoniumhydroxide, or alkylammonium hydroxide.
 3. The process of claim 1 whereinX is chloro or bromo.
 4. The process of claim 1 wherein inorganichydroxide is KOH, NaOH, LiOH, Mg(OH)₂, Ca(OH)₂, NH₄OH, NR₄OH, or acombination thereof.
 5. The process of claim 1 wherein said contactingis performed in the presence of a catalyst.
 6. The process of claim 5wherein the catalyst is a crown ether, a cryptand, sodium iodide, or acombination thereof.
 7. The process of claim 1 wherein the carboxylateis sodium acetate, potassium acetate, ammonium acetate, sodium benzoate,potassium benzoate, ammonium benzoate, or a combination thereof.
 8. Theprocess of claim 1 comprising contacting a compound of Formula IV

wherein X is halogen, with an inorganic hydroxide to provide a compoundof Formula III:


9. The process of claim 8 wherein the compound of Formula IV is producedby contacting 3,4,-alkylenedioxythiophene with 3-halo-1,2-propanediol inthe presence of an acid to provide a compound of Formula IV.